Convertible conductor stringing assembly for power line use

ABSTRACT

Convertible conductor stringing assembly for use when installing a power conductor along a power line and usable in a variety of modes to accommodate different conditions. The conductor handing sheave assembly is supportable selectively in various positions in a mounting bracket detachably securable to a pole line cross arm. The stringing block sheave is pivotable from one of its several normal stringing positions to a postion for transfer of the conductor directly into clamping position on an insulator supported on the cross arm. The stringing block mounting assembly readily accommodates a wide range of cross arm sizes.

United States Patent [1 1 Lindsey et al.

[ CONVERTIBLE CONDUCTOR STRINGING ASSEMBLY FOR POWER LINE USE [75] Inventors: L. E. Lindsey, Pasadena; Herbert F.

Sammons, Glendale, both of Calif.

[73] Assignee: Lindsey Manufacturing Company, Pasadena, Calif.

[22] Filed: Nov. 23, 1973 [21] Appl. No.: 418,469

Related U.S. Application Data [60] Division of Ser. No. 259,315, June 2, 1972, which is a continuation of Ser. No. 55,056, July 15, 1970,

abandoned.

[52] U.S. Cl. 248/228; 248/316 A; 24/263 A; 269/243 [51] Int. Cl A47b 96/00 [58] Field of Search 248/228, 226 B, 316 A; 24/263 A, 263 LS, 73 LA, DIG. 25; 269/243 [56] References Cited UNITED STATES PATENTS 2,039,369 5/1936 Travani 24/263 A June 17, 1975 2,993,254 7/1961 Larson 24/263 A 3,443,831 5/1969 Grange 24/263 A FOREIGN PATENTS OR APPLICATIONS 502,058 1954 Italy 269/243 Primary ExaminerRoy D. Frazier Assistant Examiner-Robert A. Hafer Attorney, Agent, or Firm-Sellers and Brace 5 7] ABSTRACT 6 Claims, 10 Drawing Figures PATENTEDJUN 1 mm 3,889,911

SHEET 3 CONVERTIBLE CONDUCTOR STRINGING ASSEMBLY FOR POWER LINE USE This application is a division of our copending application for US. Letters Patent, Ser. No. 259,315, filed June 2, 1972 which application is a continuation of our application for U.S. Letters Patent, Ser. No. 55,056, filed July 15, 1970, now abandoned.

This invention relates to conductor stringing devices, and more particularly to a unique conductor stringing assembly readily convertible for use while secured directly to a power line insulator or alternatively while secured to a cross arm supporting the insulator.

Modern power line designs are undergoing rapid change owing to many factors including improvements in construction materials, new and greatly improved components, and the ability of equipment to handle ever higher voltages. These and the like factors introduce new problems as respects equipment employed to install conductors, and particularly as respects stringing accessories employed temporarily at each insulator while pulling the conductor into place along the power line and thereafter to transfer the conductor onto the insulator.

Owing to the great variety of modes of supporting the insulator and changes in the insulator sizes and designs, power companies have found that hardware purchased for use on one power line is quite unsuitable for use on a different line and under different conditions. For example, if the conductor stringing sheave of prior equip ment is designed for support on the cross arm for a particular size insulator then it is quite unsuitable for use with an insulator of substantially different size. Alternatively if the prior stringing sheave is designed for use beside an upright insulator it is unusable to install a conductor on a horizontally supported insulator or on one inclined to the vertical.

in view of the foregoing and other numerous shortcomings of prior conductor stringing equipment, it is the purpose of the present invention to provide a unique and highly versatile convertible conductor stringing assembly usable in a great variety of ways in connection with insulators varying widely in diameter, height and relationship to the horizontal plane as well as on different size cross arms. To this end the invention construction comprises a sheave sub-assembly having a mounting shank selectively securable in a variety of positions in either of two types of supports, one of which is clampable about the body of the insulator itself, and the other of which is clampable to the insulator support cross arm. The sheave sub-assembly is provided with a multi-position hinging connection between the sheave proper and its supporting shank normally locked in a selected position. After the conductor has been hauled into its operating position the hinging connection is unlocked to permit lateral pivoting of the sheave to dump the conductor onto the insulator.

The stringing assembly is clampable with equal facility to an insulator supported horizontally, vertically or at any intermediate inclination. The alternate mounting clamp for the stringing sheave has simple but versatile means for rigidly clamping the same to a cross arm. This clamp is so designed that it is securable with equal rigidity to cross arms of widely varying size and tolerance variations, including both the vertical and horizontal thicknesses of the cross arms.

Accordingly it is a primary object of the present invention to provide a unique, convertible, conductor stringing assembly mountable directly on a cross arm closely adjacent an insulator to which a strung conductor is to be transfered.

Another object of the invention is the provision of a convertible conductor stringing assembly comprising an insulator clamping sub-assembly, a cross arm clamping sub-assembly to support a stringing block subassembly.

Another object of the invention is the provision of an improved conductor stringing sub-assembly having a sheave pivotally secured to one end of the mounting arms having its other end equipped with a mounting shank selectively securable in various positions on a support therefor which support is temporarily anchorable to an insulator supporting cross arm.

Another object of the invention is the provision of a conductor stringing sub-assembly mountable beside an insulator with the plane ofthe sheave normal or at some selected inclination parallel to the insulator axis, and having its stringing sheave pivotable between a normal conductor stringing position and a second position convenient for the transfer of the conductor from the sheave onto the insulator.

Another object of the invention is the provision of the mounting support for a conductor stringing subassembly which is clampable rigidly to an insulator cross arm irrespective of wide variations in the size and tolerances of the cross arm.

Another object of the invention is the provision of a supporting accessory for a conductor stringing assembly designed for automatically clamping the support against all four surfaces of a power line cross arm and for automatically accommodating the support to a particular cross arm size as the clamping bolts are tightened.

These and other more specific objects will appear upon reading the following specification and claims and upon considering in connection therewith the attached drawing to which they relate.

Referring now to the drawing in which a preferred embodiment of the invention is illustrated:

FIG. is a vertical side view of the invention convertible conductor stringing assembly secured to a cross arm closely beside an upright insulator and including a dotted line showing of the sheave pivoted to a position to transfer the conductor onto an insulator;

FIG. 2 is a vertical cross sectional view taken generally along broken line 2-2 on FIG. 1;

FIG. 3 is a fragmentary cross sectional view taken generally along line 33 on FIG. 1;

FIG. 4 is a fragmentary view taken along line 44 on FIG. 1;

FIG. 5 is a fragmentary view taken along line 55 on FIG. 1;

FIG. 6 is a fragmentary view taken along line 66 on FIG. 2;

FIG. 7 is an elevational view generally similar to FIG.

1 but showing the stringing subassembly supported FIG. 9 is a fragmentary view on an enlarged scale and partly in cross section taken along line 9-9 on FIG. 7; and

FIG. 10 is a view similar to FIG. 7 but showing the stringing assembly in its normal operating position when clamped to the body of the horizontally supported insulator.

Referring initially more particularly to FIGS. 16, there is shown an illustrative embodiment of the convertible stringing assembly, designated generally 10, comprising a sheave sub-assembly ll rigidly clamped in a cross arm mounting sub-assembly 12. The latter sub-assembly 12 is shown secured to a typical cross arm 13 beside an upright insulator 14 mounted on the cross arm.

The sheave sub-assembly 11 has an elongated rigid main body 16 cast from suitable material such as high strength lightweight alloy. Deeply grooved sheave 18 is provided with anti-friction bearings 19 (FIG. 3) and is supported on a sub-shaft 20 having a bifurcated head 21 at one end hingedly connected by hinge pin 23 to the upper end of the main body 16.

Sheave 18 is secured in place on shaft 20 by a radial arm 25 held telescoped over the outer end of the shaft by a keeper pin 26. The upper curved end of arm 25 overlies the sheave groove and pivotally supports a keeper 28 by means of a pivot pin 29. Guard 28 is generally L-shaped and its longer leg 30 is provided with a large opening to receive the upper end of arm 25. The conductor guard is held normally in the position shown in FIG. 1 by a torsion spring 32, the outer transverse end of its leg 30 engaging the outer edge of arm 25. Further clockwise rotation of the guard is therefore prevented and the conductor seated on the sheave is held positively captive until the guard is manually rotated counterclockwise to the position indicated in dot and dash lines in FIG. 1.

Referring now more particularly to FIGS. 104, the means for selectively locking sheave 18 in a desired angular position relative to its main supporting body 16 will be described. One arm of the bifurcated end 21 of the sheave supporting shaft is longer than the other as is best shown in FIG. 3 and its exterior surface is provided with an arcuate row of teeth 36 which interlock with teeth 36' on the adjacent face of a sector 37 fixed to the hinge pin 23. This sector is provided with an arcuate slot 38 desirably having a length of at least 90. Protruding downwardly from the periphery of sector 37 is a locking lug 39 rotatable past the end of a latching pin 40 (FIGS. 1, 2). Latching pin 40 is supported for axial reciprocation within a well 42 of a boss 43 integral with main body 16, and an opening through a second boss 44 of the main casting and is normally urged to its latching position by a compression spring 45 housed in well 42. An operating handle 46 for the latch pin is normally held against the underside of boss 44 by spring 45. The inner end of handle 46 protrudes into the path of a stop pin 47 anchored in boss 44 as is evident from FIG. 1. A lug 48 cooperates with the upper end of latch 40 to holdlocking lug 39 normally captive in the position shown in FIG. 1. However, when the latch pin 40 is depressed it will be evidence that lug 39 together with sector 37 and sheave 18 are free to rotate clockwise about the axis of hinge pin 23.

Normally sector 37 is held locked in a desired adjusted position relative to arm 35 of shaft 20 by means of a threaded shank 50 (FIG. 3). This shank is fixed to arm 35 and protrudes through arcuate slot 38. When a lock nut 51 carried by shank 50 is loosened, sector 37 and pin 23 can be shifted outwardly to disengage teeth 36,36, thereby permitting sector 37 to be rotated through a limited arc relative to teeth 36. This permits detent 39 to be repositioned relative to the latch pin 40 to lock sheave 18 in a desired different stringing plane. When so adjusted lock nut 51 is tightened to lock teeth 36,36 in the new position. As shown in FIG. 1, the parts are locked together to support the sheave in a vertical plane while stringing the conductor. Under other operating conditions it might be desirable that the sheave be supported in a plane inclined to the vertical either to the right or to the left of the position shown in FIG. 1. Once the latch pin 40 is depressed however, the sheave and its supporting shaft 20 are free for rotated counterclockwise pivoting, such as to the position shown in FIG. 1 with the conductor 53 properly positioned for transfer into the seating groove 54 or a suitable clamping device carried at the top of insulator 14.

CROSS ARM MOUNTING SUB-ASSEMBLY The cross arm mounting accessory 12 for the sheave will now be described with particular reference to FIGS. 1, 2, 5 and 6. This sub-assembly includes an upper generally cross-shaped casting 55 and a lower channel-shaped clamping member 56.

The arm of plate 55 extending lengthwise of the cross arm is formed with a deep slot 58 opening upwardly and through its opposite ends and having a snug sliding fit with the triangular shaped flat mounting shank 59 projecting from the lower end of the main body 16 of the sheave sub-assembly. The upper rim edges of slot 58 are contoured as is best shown in FIG. 6 and include a horizontal seating surface 60, a left hand seating surface 61 inclined at 45 to the horizontal and a right hand seating surface 62 inclined at 30 to the horizontal. The side walls of slot 58 are provided with three sets of aligned openings 63,64,65 similarly located relative to the associated surfaces 60,61,62 and receptive of a locking pin 66 to lock the sheave sub-assembly seated against any selected set of seating surfaces 60,61,62 and in different angular positions relative to cross arm 13. For example, when the sheave main body is locked assembled in the position shown in FIG. 1, main body 16 lies generally in an upright plane, whereas if it is locked against surface 61 it is inclined at an angle of 45 to the cross arm and if it is locked against surface 62 then it is inclined at an single of 60 to the cross arm.

The other arm of mounting plate 55 extends crosswise of the cross arm and is provided with shouldered slots 69,70 to seat the headed end of the similar clamping bolts 71,72. The headed ends of these bolts are provided with cross pins 73,74 fixed to the respective bolts and best shown in FIG. 2. the ends of cross pins 73 engage the inclined camming surfaces 75 along either side of slot 69 and which serve to cam bolt 71 against the left hand side of cross arm 13 as viewed in FIG. 2 as these bolts are tightened.

Similar camming surfaces on either side of slot cooperate to form V-shaped notches 76 and cooperate with pin 74 on the bolt 72 for a similar purpose as that just described. As will be evident, pin 74 may be located in the trough of the notches or at some position along the side walls of these notches at the start of a tightening operation on the thumb nuts 78 provided for each bolt. If the cross arm is a very narrow one cross pin 74 will be seated in the innermost one of the notches. whereas if it is of wider construction then it would be seated in one of the other notches as is appropriate. Any further adjusting action required will be provided by the inclined camming surfaces 75 in notches 69 seating bolt 71.

It is also to be noted from FIG. 2 that each sidewall of slots 69 and 70 is deeply notched at 80 to seat the outer handle end of the locking pin 66 utilized to lock the sheave subassembly to the upper clamping plate. Accordingly, whenever this pin is in its assembled position it is held against disassembly by gravity rotation of its shorter leg into the adjacent one of notches 80.

INSULATOR SUPPORTED CLAMPING SUBASSEMBLY Referring now to FIGS. 7-9, there is shown an alternate mounting sub-assembly 12' for supporting sheave sub-assembly 11 against the side of a rigidly supported insulator 14'. In FIG. 7, the insulator 14 is mounted in an upright position on a cross arm 13', whereas in FIG. it is mounted and supported horizontally on the outer end of a pole supported bracket 13''. Mounting sub-assembly 12 comprises a cast main body 85 having a deep groove 86 shaped to embrace any of a wide range of insulator diameters. Its opposite longitudinal edges are preferably capped with thick elastomeric material 87 which seats against the exterior of the insulator and avoids overstressing or damaging the insulator.

Main body 85 is held rigidly clamped in any desired position lengthwise of the insulator by a wide flexible clamping band 88 preferably heavily coated with elastomeric material 89. The opposite ends of the clamping band are looped and one end seats over an anchor pin 90 and the other end is similarly attached to a pin 92 carried crosswise of the head of bolt 93. The threaded shank 94 of this bolt passes through an opening in one rim edge of main body 85 and supports a semicylindrical shaped washer 95 beneath a clamping nut 96. Tightening nut 96 locks the mounting subassembly 12' rigidly to the insulator. Preferably, the opening accommodating bolt 93 opens laterally through the edge of the main body as is indicated at 97 in FIG. 9, thereby facilitating the assembly and disassembly of unit 12 to an insulator.

Extending lengthwise of the exterior side of main body 85 is a deep slot 100 (FIG. 8) to receive mounting shank 59 of the main body of the sheave unit. Slot 100 is generally L-shaped and includes a longer leg extending lengthwise of main body 85 and a shorter leg 102 (FIGS. 7, 10) projecting generally radially relative to the clamping band 88. Each of these legs is provided with mounting holes, 63, 64', 65' corresponding to holes 63, 64, 65 (FIG. 6) in which the assembly pin 66 can be seated to lock shank 59 assembled to its mounting clamp 12'. FIGS. 7 and 10 show but two of the several possible modes of securing sheave sub-assembly 11 to the flexible band-type mounting unit 12.

While the particular convertible conductor stringing assembly for power line use herein shown and disclosed in detail is fully capable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that it is merely illustrative of the presently preferred embodiment of the invention, and that no limitations are intended to the details of construction or design herein shown other than as defined in the appended claims.

We claim:

1. A support assembly clampable to a rigid four-sided member of different widths, said assembly comprising first and second clamping plates wider than the width of the four-sided member, said plates interconnected by at least two bolts, each said bolt having a shank with a radial projection adjacent one end thereof, at least one of said plates having slots formed by intersecting walls extending crosswise of the width of the four-sided member and receiving the shanks of bolts interconnecting said clamping plates, the points of intersection of said walls of said slots being spaced apart less than the width of the narrowest four-sided member to which said support assembly is to be clamped, the sides of at least one of said slots having sloping surfaces inclined relative to the adjacent side of said member and cooperating with said radial projection means on the shanks of said bolts to cam the shanks of said bolt toward the adjacent side of said four-sided member as said bolts are tightened whereby said plates and said bolts are forced into firm contact with the juxtaposed surfaces of said member.

2. A support assembly as defined in claim I characterized in that one of said plates includes a pair of spaced apart walls the adjacent surfaces of which cooperate to form a seating socket for the shank end of a conductor stringing block assembly, and pairs of aligned bores through said spaced apart walls accommodating pin means usable to lock a stringing block assembly detachably in a selected pair of aligned bores.

3. A support assembly as defined in claim 1 characterized in that said first plate has an elongated slot along and generally normal to an adjacent face of a four-sided member, the sides of each of said slots having sloping surfaces inclined to the adjacent face of said four-sided member and cooperable with the radial projection means on the shank of a respective one of said bolts to cam the bolt toward the face of said four-sided member as said bolts are tightened.

4. A mounting bracket for a conductor stringing block assembly readily anchorable to an insulator cross arm of different widths, said bracket comprising first and second plates adapted to seat against the upper and lower surfaces of an insulator supporting cross arm, one of said plates having elongated slots on opposed edges thereof and extending crosswise of said cross arm, the other of said plates having openings including at least one elongated slot vertically aligned with said first mentioned slots, at least one of said first mentioned slots being formed by converging sidewalls, at least one clamping bolt connecting said plates, said clamping bolt having a cross head extending transversely of the axis of said bolt, said one of said first mentioned slots seating the cross head of the respective clamping bolt, said clamping bolt having a threaded end thereof extending through an opening in said other bracket plate, and said converging sidewalls being effective to cam said clamping bolt against the adjacent vertical face of the cross arm as said bolts are tightened.

5. A bracket as defined in claim 4 characterized in that the upper one of said bracket plates includes a long deep channel opening upwardly and having different portions of the upper edges of its sidewalls inclined at different angles to a vertical plane extending crosswise of said channel, said channel and said inclined edges being adapted to seat the lower shank end of a stringing block assembly in different positions, and pin means cooperating with pairs of aligned bores through the sidewalls of said channel to anchor a stringing block assembly detachably in any selected aligned pair of said bores.

6. A bracket as defined in claim characterized in said projecting means is seated in said retaining notch. 

1. A support assembly clampable to a rigid four-sided member of different widths, said assembly comprising first and second clamping plates wider than the width of the four-sided member, said plates interconnected by at least two bolts, each said bolt having a shank with a radial projection adjacent one end thereof, at least one of said plates having slots formed by intersecting walls extending crosswise of the width of the four-sided member and receiving the shanks of bolts interconnecting said clamping plates, the points of intersection of said walls of said slots being spaced apart less than the width of the narrowest foursided member to which said support assembly is to be clamped, the sides of at least one of said slots having sloping surfaces inclined relative to the adjacent side of said member and cooperating with said radial projection means on the shanks of said bolts to cam the shanks of said bolt toward the adjacent side of said four-sided member as said bolts are tightened whereby said plates and said bolts are forced into firm contact with the juxtaposed surfaces of said member.
 2. A support assembly as defined in claim 1 characterized in that one of said plates includes a pair of spaced apart walls the adjacent surfaces of which cooperate to form a seating socket for the shank end of a conductor stringing block assembly, and pairs of aligned bores through said spaced apart walls accommodating pin means usable to lock a stringing block assembly detachably in a selected pair of aligned bores.
 3. A support assembly as defined in claim 1 characterized in that said first plate has an elongated slot along and generally normAl to an adjacent face of a four-sided member, the sides of each of said slots having sloping surfaces inclined to the adjacent face of said four-sided member and cooperable with the radial projection means on the shank of a respective one of said bolts to cam the bolt toward the face of said four-sided member as said bolts are tightened.
 4. A mounting bracket for a conductor stringing block assembly readily anchorable to an insulator cross arm of different widths, said bracket comprising first and second plates adapted to seat against the upper and lower surfaces of an insulator supporting cross arm, one of said plates having elongated slots on opposed edges thereof and extending crosswise of said cross arm, the other of said plates having openings including at least one elongated slot vertically aligned with said first mentioned slots, at least one of said first mentioned slots being formed by converging sidewalls, at least one clamping bolt connecting said plates, said clamping bolt having a cross head extending transversely of the axis of said bolt, said one of said first mentioned slots seating the cross head of the respective clamping bolt, said clamping bolt having a threaded end thereof extending through an opening in said other bracket plate, and said converging sidewalls being effective to cam said clamping bolt against the adjacent vertical face of the cross arm as said bolts are tightened.
 5. A bracket as defined in claim 4 characterized in that the upper one of said bracket plates includes a long deep channel opening upwardly and having different portions of the upper edges of its sidewalls inclined at different angles to a vertical plane extending crosswise of said channel, said channel and said inclined edges being adapted to seat the lower shank end of a stringing block assembly in different positions, and pin means cooperating with pairs of aligned bores through the sidewalls of said channel to anchor a stringing block assembly detachably in any selected aligned pair of said bores.
 6. A bracket as defined in claim 5 characterized in that said pin means includes means projecting outwardly from the main body adjacent one end thereof which means is rotatable into and out of a retaining notch of said upper bracket plate and effective to hold said pin means locked in assembled position so long as said projecting means is seated in said retaining notch. 